JP2014522574A - Apparatus and method for supporting and controlling a substrate - Google Patents

Abstract

  Embodiments of the present invention provide an apparatus and method for supporting and controlling a substrate during thermal processing. One embodiment of the present invention provides an apparatus for processing a substrate. The apparatus includes a chamber body defining an inner volume, a substrate support disposed within the inner volume, and an assist force assembly configured to apply assist force to the substrate. Another embodiment provides a gas supply assembly configured to adjust the thermal mass of a fluid flow supplied to position, control, and / or rotate the substrate.

Description

  Embodiments of the present invention generally relate to an apparatus and method for processing a substrate. More particularly, embodiments of the present invention provide an apparatus and method for supporting a substrate during thermal processing.

  During semiconductor processing, particularly during heat treatment, a substrate supported by a conventional substrate support may be warped, curved, or even ruptured due to a thermal gradient caused by rapid heating. In some cases, when the substrate is deformed, different regions of the substrate are exposed to the heat source in different ways due to the deformation, and the entire substrate may become thermally non-uniform.

  Accordingly, there is a need for an improved apparatus and method for supporting and controlling a substrate during thermal processing.

  Embodiments of the present invention generally provide an apparatus and method for processing a substrate. More particularly, embodiments of the present invention provide an apparatus and method for handling a substrate during thermal processing.

  One embodiment of the present invention provides an apparatus for processing a substrate. The apparatus includes a chamber body defining an inner volume, a substrate support disposed within the inner volume, and an assist force assembly configured to apply assist force to the substrate. The substrate support includes a substrate support body having an upper surface. A plurality of ports are formed on the upper surface. These ports are configured to supply a plurality of fluid streams to support, position, and / or rotate the substrate over the top surface. The assist force is configured to adjust the vertical position of the substrate or the profile of the substrate.

  Another embodiment of the invention provides a method of handling a substrate. The method includes providing a plurality of fluid streams to a plurality of ports formed on a top surface of a substrate support in a processing chamber and a plurality of fluid streams such that the substrate floats over the top surface of the substrate support. Receiving the substrate on the substrate and applying an assist force to the substrate so as to reduce deformation of the substrate without directly contacting the substrate.

  Yet another embodiment of the present invention provides a method of handling a substrate during thermal processing. The method includes providing a plurality of fluid streams to a plurality of ports formed on a top surface of a substrate support in a processing chamber and a plurality of fluid streams such that the substrate floats over the top surface of the substrate support. Receiving the substrate, monitoring the temperature profile of the substrate, and adjusting one or more thermal masses of the plurality of fluid streams to adjust the temperature profile of the substrate.

  In order that the above features of the present invention may be understood in detail, a more detailed description of the invention, briefly summarized above, may be obtained by reference to the embodiments. Some of these embodiments are illustrated in the accompanying drawings. However, since the present invention may also permit other equally valid embodiments, the accompanying drawings show only typical embodiments of the invention and therefore should not be considered as limiting the scope of the invention. Please keep in mind.

1 is a schematic cross-sectional side view of a heat treatment chamber according to an embodiment of the present invention. 1B is a schematic top view of the heat treatment chamber of FIG. 1A with the lamp assembly removed. FIG. FIGS. 1A to 1D schematically illustrate a substrate having improved flatness in response to a reaction force according to an embodiment of the present invention. FIG. 3 schematically illustrates a substrate support having a plurality of ports for supporting a substrate and an electrostatic chuck for applying a reaction force according to an embodiment of the present invention. 2 is a flow diagram of a method for supporting a substrate with improved thermal uniformity, according to an embodiment of the invention. 3 is a flow diagram of a method for maintaining substrate flatness, according to an embodiment of the invention.

  To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to multiple figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized in other embodiments without specific description.

  Embodiments of the present invention generally relate to a method and apparatus for processing a substrate. In particular, embodiments of the present invention provide an apparatus and method for supporting a substrate during thermal processing. Embodiments of the present invention handle a substrate using fluid flow, adjust substrate temperature using an adjustable fluid composition, and / or flatten the substrate using an assist force against the fluid flow. By maintaining the degree, a processing chamber is provided that provides improved substrate control during processing.

  FIG. 1A is a schematic cross-sectional side view of a thermal processing chamber 100 according to one embodiment of the present invention. The thermal processing chamber 100 is configured to perform rapid thermal processing of the substrate.

  The thermal processing chamber 100 includes a sidewall 102, a chamber bottom 104 coupled to the sidewall 102, and a quartz window 106 disposed on the sidewall 102. Side wall 102, chamber bottom 104, and quartz window 106 define an inner volume 108 for processing substrate 110. A heating assembly 112 is disposed over the quartz window 106, and the heating assembly 112 is configured to induce thermal energy through the quartz window 106 toward the inner volume 108. The heating assembly 112 includes a plurality of heating elements 114. In one embodiment, the plurality of heating elements 114 are a plurality of lamps. The plurality of heating elements 114 can be controlled by the system controller 152. In one embodiment, the plurality of heating elements 114 can be controlled individually or collectively.

  A slit valve door 116 can be formed through the sidewall 102 for transferring the substrate. The thermal processing chamber 100 is coupled to a gas source 118 configured to provide one or more processing gases to the inner volume 108 during processing. A vacuum pump 120 for pumping the inner volume 108 can be coupled to the heat treatment chamber 100.

  FIG. 1B is a schematic top view of the thermal processing chamber 100 of FIG. 1A with the heating assembly 112 removed.

  A substrate support 122 is disposed within the inner volume 108, and the substrate support 122 is configured to support, position, and / or rotate the substrate 110 during processing. Specifically, the substrate support 122 is a non-contact substrate support device that uses fluid flow to support, position, and / or rotate the substrate 110.

  In one embodiment, the substrate support 122 includes a substrate support body 124 disposed on the chamber bottom 104. A plurality of ports 126 are formed on the upper surface 128 of the substrate support body 124. FIG. 1B illustrates an exemplary configuration of multiple ports 126 according to one embodiment of the invention.

  The plurality of ports 126 are connected to the fluid supply system 132 through a plurality of channels 130 formed in the substrate support body 124. In one embodiment, the fluid supply system 132 is configured to supply one or more gases, such as nitrogen, helium, argon, krypton, neon, hydrogen, or combinations thereof. Alternatively, fluid supply system 132 can be configured to supply a plurality of ports 126 with a flow of liquid, such as water.

  The plurality of ports 126 direct a plurality of fluid streams toward the bottom surface 134 of the substrate 110 to the substrate region near the top surface 128, and the friction and transmission generated when the fluid stream impinges on the bottom surface 134 of the substrate 110. It is configured to support and move the substrate 110 using the momentum that is provided. The substrate 110 is supported, positioned, and / or rotated within the substrate region by controlling the characteristics of the fluid flow supplied from the plurality of ports 126, such as the speed and direction of the plurality of fluid flows. The forces transmitted by each fluid flow can be combined to move and position the substrate 110 as needed.

  A detailed description of an exemplary substrate positioning assembly using fluid flow can be found in U.S. Patent Application Publication No. 2008/0280453 entitled “Apparatus and Method for Supporting, Positioning and Rotating in Substrating in a Processing Chamber”. it can.

  The thermal processing chamber 100 can include a plurality of thermal sensors 136 configured to measure the temperature of the substrate 110 at various locations. The plurality of thermal sensors 136 can be disposed in an opening formed through the chamber bottom 104. In one embodiment, the plurality of thermal sensors 136 are pyrometers. As shown in FIG. 1B, a plurality of thermal sensors 136 may be arranged at different radial positions to measure the temperature of the substrate 110 at different radial positions and generate a temperature profile of the substrate 110 being processed. it can. The plurality of thermal sensors 136 are coupled to the system controller 152. In one embodiment, the system controller 152 can be configured to generate a thermal profile for the substrate 110 using signals received from the plurality of thermal sensors 136.

  The thermal processing chamber 100 also includes two or more position sensors 138 configured to detect the position of the substrate 110 within the thermal processing chamber 100. In one embodiment, position sensor 138 is a capacitive sensor configured to detect the relative position of the fluoroscopic portion of substrate 110. A plurality of position sensors 138 are coupled to the system controller 152. The position sensor 138 can be used together or alone to determine various characteristics of the substrate 110 such as vertical position, horizontal position, horizontality, flatness, rotational speed, rotational direction, and the like. A detailed description of using capacitive sensors to detect substrate characteristics can be found in US patent application Ser. No. 12 / 611,958, entitled “Apparatus and Methods for Positioning a Substituting Capacitive Sensors”.

  Alternatively, the position sensor 138 can be an optical sensor or other sensor suitable for detecting the position of the substrate 110.

  In accordance with one embodiment of the present invention, the substrate support 122 is heated to provide thermal energy to the back side of the substrate 110. In one embodiment, the substrate support 122 includes a heater 140 embedded within the substrate support body 124. In one embodiment, the heater 140 may be a resistance heater. A heater power supply 142 can be coupled to the heater 140. The substrate 140 may be directly heated by the heater 140 to provide thermal energy to the substrate 110 by thermal radiation and convection due to fluid flow between the substrate 110 and the upper surface 128 of the substrate support body 124. In one embodiment, the heater 140 can be maintained at a temperature of about 450 ° C. to about 720 ° C. during processing. The heater power supply 142 can be coupled to the system controller 152 and controlled by the system controller 152.

  According to an embodiment of the present invention, the fluid supply system 132 is configured to supply a plurality of ports 126 with a fluid flow having an adjustable thermal mass to adjust the temperature of the substrate 110.

  In one embodiment, the fluid supply system 132 can supply a fluid stream having an adjustable thermal mass by adjusting the composition of the fluid stream. The fluid supply system 132 can include two or more fluid sources 144A, 144B. The fluid supply system 132 also includes a plurality of fluid control devices 146. Each fluid control device 146 is connected between one of the plurality of ports 126 and two or more fluid sources 144A, 144B. Each fluid control device 146 is configured to regulate the flow rate supplied to the corresponding port 126.

  In one embodiment, each fluid control device 146 can also adjust the ratio of fluid from the fluid sources 144A, 144B to adjust the composition of the fluid flow supplied to the corresponding port 126. The fluid source 144A is configured to provide a fluid having a different thermal mass than the fluid provided by the fluid source 144B. By adjusting the composition of the fluid stream provided to each port 126, the fluid supply system 132 can adjust the thermal mass of the fluid stream supplied to each port 126. In one embodiment, each fluid control device 146 can be individually controlled by the system controller 152.

  The substrate support 122 is configured to apply an assist force to the substrate region to balance or react to the fluid flow from the plurality of ports 126 on the substrate 110 in the substrate region. Further includes an assist force assembly.

  In one embodiment, the assist force assembly can be configured to apply a downward force in the vertical direction by a vacuum. The assist force assembly can include a plurality of vacuum ports 148 connected to the vacuum source 150. In one embodiment of the present invention, the plurality of vacuum ports 148 are open on the upper surface 128 of the substrate support body 124. The plurality of vacuum ports 148 are connected to the vacuum source 150. The plurality of vacuum ports 148 can be distributed at various locations to balance or counteract the forces from the fluid flow supplied from the plurality of ports 126. In one embodiment, each of the plurality of vacuum ports 148 can be individually controlled by the system controller 152.

  During processing, the thermal sensor 136, the position sensor 138, the fluid supply system 132, the vacuum port 148, and the system controller 152 form a closed loop control system that controls the characteristics of the substrate 110 to achieve the desired processing results.

  As discussed above, the substrate support 122 is configured to support, position, and / or rotate the substrate 110 with fluid flow from the plurality of ports 126 while the substrate support body 124 can be heated. The substrate 110 floats on the substrate support 122 without any solid contact with the substrate support body 124.

  The heat flux between the substrate 110 and the substrate support body 124 varies the fluid flow through the plurality of ports 126 and / or adjusts the distance 154 between the substrate and the upper surface 128 of the substrate support body 124. By doing so, it can be controlled.

  Varying the fluid flow may include adjusting the flow rate from the plurality of ports 126 and / or adjusting the composition of the fluid flow from the plurality of ports 126.

  When other conditions such as heater 140 temperature, fluid flow composition, and distance 154 remain the same, the temperature of the substrate 110 decreases as the flow rate increases. Therefore, as a result of increasing the flow rate from the plurality of ports 126, the temperature in the substrate 110 can be lowered, and as a result of reducing the flow rate from the plurality of ports 126, the temperature in the substrate 110 can be raised.

  As discussed above, fluid source 144A is configured to provide a fluid having a different thermal mass than the fluid provided by fluid source 144B. In one embodiment, fluid source 144A is a helium source and fluid source 144B is a nitrogen source. Usually, nitrogen gas has a higher thermal mass than helium gas. When other conditions such as the temperature of the heater 140, the flow rates from the plurality of ports 126, and the distances 154 remain the same, the substrate 110 will cause the substrate 110 to move when helium gas is used to support the substrate 110. It has a higher temperature when the same flow of nitrogen gas is used to support.

  For example, when the heater 140 is maintained at a temperature of about 720 ° C., the inner volume 108 is maintained at atmospheric pressure, and a flow rate of about 500 sccm to 2500 sccm is used to support the substrate 110, the temperature of the substrate 110 is helium. When gas is used, it is about 60 ° C. higher than when the same flow of nitrogen gas is used. Thus, when a mixture of nitrogen and helium is used to support the substrate 110, the temperature of the substrate 110 can vary within a range of about 60 ° C. When other processing conditions remain the same, increasing the ratio of nitrogen in the nitrogen / helium mixture used to support the substrate 110 can reduce the temperature of the substrate 110 and reduce the nitrogen ratio. By reducing the temperature, the temperature of the substrate 110 can be increased.

  Thus, increasing the ratio of fluid with higher thermal mass from the plurality of ports 126 can result in a decrease in the temperature of the substrate 110 and reducing the ratio of fluid with higher thermal mass from the plurality of ports 126. The temperature of the substrate 110 can be increased.

  By increasing the distance 154, the substrate 110 approaches the heating assembly 112 and moves away from the substrate support body 124. Therefore, the temperature of the substrate 110 can be changed by adjusting the distance 154. The distance 154 can be controlled by varying the fluid flow from the plurality of ports 126 or by applying an auxiliary force to balance the lift from the plurality of ports 126. Increasing the flow rate from the port 126 configured to lift the substrate 110 vertically can increase the distance 154 and reduce the flow rate from the port 126 configured to lift the substrate 110 vertically. Thus, the distance 154 can be reduced.

  Auxiliary force can be applied and / or adjusted to adjust the distance 154. When it is beneficial not to change the flow rate, an auxiliary force can be applied to change the distance 154. In one embodiment, the assist force can be pre-applied with fluid flow from the plurality of ports 126 and can be reduced or increased during processing to change the distance 154. In one embodiment, the assist force can be applied by a vacuum load through a plurality of vacuum ports 148.

  In one embodiment, an auxiliary force, such as a vacuum force from the vacuum port 148, is pre-applied or always applied to maintain substrate flatness during processing. By maintaining the flatness of the substrate 110 while the substrate 110 is levitating, regardless of the thermal gradient in the substrate 110 caused by heating assembly 112, heating of the heater 140, or other heating, the substrate 110 is It becomes possible to expand freely in the radial direction during the heat treatment. As a result, the curvature, warpage, and / or breakage of the substrate 110 during rapid thermal processing is reduced. Furthermore, by maintaining the flatness of the substrate 110, different regions of the flat substrate are positioned at the same distance from the heating source, ensuring uniformity of temperature within the substrate 110.

  2A-2D schematically illustrate a substrate having improved flatness in response to reaction forces, according to an embodiment of the present invention.

  FIG. 2A schematically shows that the substrate 110 is subjected to gravity G and is curved downward near the center, and that the support fluid flow 202 is applied to the outer region of the substrate 110. In FIG. 2B, an auxiliary force 204 is applied to the substrate 110 at a position outside the fluid flow 202 in the radial direction. As a result of the combination of auxiliary force 204, lift from fluid flow 202, and gravity G, substrate 110 becomes flat.

  FIG. 2C schematically shows that the substrate 110 is curved upward due to the thermal gradient that occurs when the upper side 206 of the substrate 110 is heated to a higher temperature than the lower side 208 of the substrate. In FIG. 2D, the auxiliary force 204 is applied to the substrate 110 at a position inside the fluid flow 202 in the radial direction. As a result of the combination of auxiliary force 204, lift from fluid flow 202, and gravity G, substrate 110 becomes flat.

  The auxiliary force assembly can be configured to apply a force to the substrate 110 by any suitable non-contact means such as vacuum force, electrostatic force, electromagnetic force, and the like.

  FIG. 3 schematically illustrates a substrate support 300 according to an embodiment of the invention having a plurality of ports 126 for supporting the substrate 110 with a fluid flow and applying an assist force by electrostatic forces. The substrate support 300 is similar to the substrate support 122 except that it includes an electrode 302 embedded within the substrate support body 124 and does not have a vacuum port 148. The electrode 302 is connected to a power source 304. The power source 304 can be connected to the system controller 152 so that the system controller 152 can apply an electrostatic force applied from the electrode 302 to the substrate 110 while the substrate 110 is levitated above the substrate support body 124. The amount of can be controlled.

  FIG. 4 is a flow diagram of a method 400 for supporting a substrate with improved thermal uniformity, according to one embodiment of the invention. The method 400 can be performed in a processing chamber similar to the processing chamber 100 described above.

  In box 410, a plurality of fluid streams are supplied to a plurality of ports formed on the top surface of the substrate support in the processing chamber. In one embodiment, the substrate support can be heated.

  At box 420, a substrate to be processed is received by a plurality of fluid streams, the plurality of fluid streams supporting the substrate on the top surface of the substrate support such that the substrate floats. The substrate does not contact the top surface of the substrate. In one embodiment, fluid flow from multiple ports can also rotate the substrate over the substrate support.

  In one embodiment, a heat treatment can be performed when the substrate floats over the substrate support. The substrate can be heated by a heater in the substrate support and / or a heat source disposed on the substrate. In one embodiment, the heat treatment can be a rapid heat treatment and the substrate is heated at a high ramp rate.

  In box 430, the flatness of the substrate can be maintained by applying an assist force to the substrate. Whether to maintain the flatness of the substrate can be optional. As shown in FIGS. 2A-2D, an auxiliary force can be applied to overcome deformation caused by gravity, fluid flow, or thermal gradients. In one embodiment, the assisting force can be pre-applied before the substrate is received and adjusted during processing. FIG. 5 describes in detail how to maintain the flatness of the substrate.

  In box 440, one or more thermal sensors may be used to generate a temperature profile for the substrate.

  At box 450, one or more processing parameters can be adjusted according to the temperature profile of the substrate obtained at box 440 to adjust a desired temperature profile, such as a uniform temperature profile across the substrate. Process parameters that are adjusted include one of the distance between the substrate and the substrate support, the flow rate of the fluid stream to support the substrate, one or more thermal masses of the fluid stream, or a combination thereof. Can do. In one embodiment, adjusting the distance between the substrate and the substrate support can include adding or adjusting the assist force. In one embodiment, the thermal mass of the fluid stream can be adjusted by adjusting the ratio of two fluids having different thermal masses in the fluid stream.

  In one embodiment, box 440 and box 450 can be executed repeatedly during processing.

  FIG. 5 is a flow diagram of a method 500 for maintaining substrate flatness while supporting a substrate with a fluid flow, according to one embodiment of the invention. Method 500 can be used in box 430 of method 400.

  In box 510, the profile of the substrate supported by the fluid stream while being processed can be monitored using one or more position sensors. In one embodiment, the position sensor can be a capacitive sensor directed toward the substrate.

  In box 520, the assist force applied to the substrate can be added or adjusted to maintain the flatness of the substrate. In one embodiment, the assist force can be a vacuum force applied through a plurality of vacuum ports formed on the top surface of the substrate support. In another embodiment, the assist force can be an electrostatic force.

  In one embodiment, box 510 and box 520 may be performed repeatedly to maintain substrate flatness during processing.

  Embodiments of the present invention have several advantages over conventional thermal processing substrate supports. For example, embodiments of the present invention provide a non-contact substrate support that controls the rate of substrate temperature ramping and process uniformity by adjusting fluid flow parameters such as fluid flow composition and / or flow rate. Improve sex. Embodiments of the present invention also reduce substrate curvature, warpage, and breakage during thermal processing by applying and / or adjusting assist forces on the substrate during processing.

  Although embodiments of the present invention have been described using RTP chambers, embodiments of the present invention can be used with any suitable chamber where thermal uniformity is required. For example, embodiments of the present invention include chemical vapor deposition chambers, atomic layer deposition chambers, thermal processing chambers with flash lamps, laser annealing chambers, physical vapor deposition chambers, ion implantation chambers, plasma oxidation chambers, or load lock chambers. Can be used within.

  While the above is directed to embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope of the invention is subject to the following patents: Determined by the claims.

Claims (16)

An apparatus for processing a substrate,
A chamber body defining an inner volume;
A substrate support body disposed within the inner volume, the substrate support body having an upper surface and a plurality of ports formed in the upper surface to supply a plurality of fluid flows to a substrate region near the upper surface. A substrate support comprising:
An auxiliary force assembly for supplying an auxiliary force within the substrate region.   The apparatus of claim 1, wherein the auxiliary force assembly comprises a vacuum source connected to a plurality of vacuum ports formed in the upper surface of the substrate support body.   The apparatus of claim 2, further comprising two or more substrate position sensors.   The apparatus of claim 2, further comprising a heater embedded in the substrate support body. A first fluid source coupled to the plurality of ports;
The apparatus of claim 4, further comprising a second fluid source coupled to the plurality of ports, wherein the first and second fluid sources provide fluids having different thermal masses.   A plurality of fluid control devices coupled between the plurality of ports and the first and second fluid sources, wherein the plurality of fluid control devices respectively from the first and second fluid sources; The apparatus of claim 5, wherein the ratio of the fluid is adjusted.   A plurality of thermal sensors disposed within the inner volume, and a heating assembly disposed over the inner volume and configured to induce thermal energy toward the substrate region above the substrate support; The apparatus of claim 4, further comprising: A method of handling a substrate,
Providing a plurality of fluid streams to a plurality of ports formed on an upper surface of a substrate support in the processing chamber;
Receiving a substrate over the plurality of fluid streams such that the substrate floats over the top surface of the substrate support;
Applying an assisting force to the substrate so as to maintain the flatness of the substrate without directly contacting the substrate.   The method of claim 8, wherein applying the assist force comprises applying an electrostatic force to the substrate.   9. The method of claim 8, further comprising heating the substrate support using a heater embedded within the substrate support.   The method of claim 8, further comprising adjusting the assist force to adjust a distance between the substrate and the top surface of the substrate. A method for controlling a substrate during heat treatment, comprising:
Providing a plurality of fluid streams to a plurality of ports formed on an upper surface of a substrate support in the processing chamber;
Receiving a substrate over the plurality of fluid streams such that the substrate floats over the top surface of the substrate support;
Monitoring the temperature profile of the substrate;
Adjusting one or more thermal masses of the plurality of fluid streams to adjust the temperature profile of the substrate.   Each fluid stream includes a first fluid and a second fluid, the first fluid having a thermal mass higher than a thermal mass of the second fluid, and one or more of the plurality of fluid streams The method of claim 12, wherein adjusting a thermal mass includes adjusting a ratio of the first fluid to the second fluid.   The method of claim 13, wherein the first fluid is helium and the second fluid is nitrogen.   The method of claim 12, further comprising applying an assist force to the substrate to maintain the flatness of the substrate without directly contacting the substrate.   The method of claim 8 or 15, wherein applying the assist force comprises applying a vacuum force to the substrate through one or more vacuum ports formed on the top surface of the substrate support.

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